1. Field of the Invention
The invention relates to sensors for detecting the presence of ice on structures, as for example, aircraft, roads, bridges, and equipment.
2. Description of the Prior Art
It is known to provide sensors to detect the presence of ice on various structures. Prior types of such sensors include hot-wire, vibrating probe, pulse-echo, microwave and pressure array types. Such devices typically are large, expensive, consume significant power, and disrupt the flow field around structures such as aircraft. Further, such devices typically are deployed for single-point measurements, such as one per aircraft, for example, providing a single reading for the entire aircraft. The sensors activate the de-icing of the whole aircraft, or other structure, without regard to local conditions wherein ice may not be present.
It is deemed desirable to have available an ice detector sensor which is small and relatively inexpensive, so that large numbers of sensors can be made and used at very low cost. It is further desired to have sensors which are of negligible weight and of a configuration so as not to disrupt flow over the surface on which the sensor is mounted. There is a need for such sensors as are adapted to be spread upon a surface to provide knowledge of ice conditions in a number of local areas of the surface. Only those local areas covered with ice would then be de-iced, saving power and de-ice chemicals in utilization of the de-icing system.